This paper discusses a spectrum of systems that cool or heat occupants personally, termed 'personal comfort systems' (PCS), in order to quantify their ability to produce comfort in ambient temperatures that are above or below the subjects' neutral temperatures.The comfort-producing effectiveness may be quantified in terms of a temperature difference, coining the index 'corrective power' (CP). CP is defined as difference between two ambient temperatures at which equal thermal sensation is achieved -one with no PCS (the reference condition), and one with PCS in use. CP represents the degree to which a PCS system may "correct" the ambient temperature toward neutrality. CP can alternatively be expressed in terms of thermal sensation and comfort survey scale units.Published studies of PCS are reviewed to extract their CP values. Cooling CP ranges from -1 to -6K, and heating CP from 2K to 10K. The physical characteristics of the particular PCS systems are not reported in detail here, but are presented as prototypes of what is possible.Deeper understanding of PCS will require new physiological and psychological information about comfort in local body segments and subsegments, and about spatial and temporal alliesthesia. These topics present many opportunities for productive future research.

This study examined the effects of personally controlled air movement on human thermal comfort and perceived air quality (PAQ) in warm-humid environments. At temperatures 26, 28, and 30°C, and relative humidity (RH) 60% and 80%, sixteen human subjects were exposed to personally controlled air movement provided by floor fans in an environmental chamber. The subjects reported their thermal sensation, thermal comfort, and PAQ during the tests. Two breaks periods with elevated metabolic levels were used to simulate normal office activities. Results show that with personally controlled air movement, thermal comfort could be maintained up to 30°C and 60% RH, and acceptable PAQ could be maintained up to 30°C 80% RH, without discomfort from humidity, air movement or eye-dryness. Thermal comfort and PAQ were resumed within 5 minutes after the breaks. The 80% acceptable limit implicit in comfort standards could be extended to 30°C and 60% RH. The average energy consumed by the fans for maintaining comfort was lower than 10W per person, making air movement a very energy-efficient way to deliver comfort in warm-humid environments.

A novel heated/cooled chair was evaluated for its effect on thermal sensation and comfort.The chair is exceptionally efficient, allowing standalone battery operation over long periods.Its capabilities at providing comfort needed to be established.Twenty-three college students participated in 69 2.25-hour tests. Four heated/cooled chairs were placed in an environmental chamber resembling an office environment. The chamber temperatures were 16°C, 18°C and 29°C. During the tests the subjects had full control of the chair power through a knob located on the chair. The heated/cooled-chair results could be compared to those of conventional mesh and cushion chairs tested in the same three environmental conditions in a previous study, as well as to a thermoelectrically heated and cooled chair.Subjective responses for thermal sensation and comfort were obtained at 15-minute intervals. The results show that the heated/cooled chair strongly influences the subjects' thermal sensation and improves thermal comfort and perceived air quality. No significant differences were found between men and women. The chair provided comfortable conditions for 92% of the subjects in a range of temperatures from 18°C to 29°C.

Recognizing the value of open-source research databases in advancing the art and science of HVAC, in 2014 the ASHRAE Global Thermal Comfort Database II project was launched under the leadership of University of California at Berkeley's Center for the Built Environment and The University of Sydney's Indoor Environmental Quality (IEQ) Laboratory. The exercise began with a systematic collection and harmonization of raw data from the last two decades of thermal comfort field studies around the world. The ASHRAE Global Thermal Comfort Database II (Comfort Database), now an online, open-source database, includes approximately 81,846 complete sets of objective indoor climatic observations with accompanying "right-here-right-now" subjective evaluations by the building occupants who were exposed to them. The database is intended to support diverse inquiries about thermal comfort in field settings. A simple web-based interface to the database enables filtering on multiple criteria, including building typology, occupancy type, subjects' demographic variables, subjective thermal comfort states, indoor thermal environmental criteria, calculated comfort indices, environmental control criteria and outdoor meteorological information. Furthermore, a web-based interactive thermal comfort visualization tool has been developed that allows end-users to quickly and interactively explore the data.